The pig as a model system for investigating the recruitment and contribution of myofibroblasts in skin healing

Abstract

In the skin-healing field, porcine models are regarded as a useful analogue for human skin due to their numerous anatomical and physiological similarities. Despite the widespread use of porcine models in skin healing studies, the initial origin, recruitment and transition of fibroblasts to matrix-secreting contractile myofibroblasts are not well defined for this model. In this review, we discuss the merit of the pig as an animal for studying myofibroblast origin, as well as the challenges associated with assessing their contributions to skin healing. Although a variety of wound types (incisional, partial thickness, full thickness, burns) have been investigated in pigs in attempts to mimic diverse injuries in humans, direct comparison of human healing profiles with regards to myofibroblasts shows evident differences. Following injury in porcine models, which often employ juvenile animals, myofibroblasts are described in the developing granulation tissue at 4 days, peaking at Days 7-14, and persisting at 60 days post-wounding, although variations are evident depending on the specific pig breed. In human wounds, the presence of myofibroblasts is variable and does not correlate with the age of the wound or clinical contraction. Our comparison of porcine myofibroblast-mediated healing processes with those in humans suggests that further validation of the pig model is essential. Moreover, we identify several limitations evident in experimental design that need to be better controlled, and standardisation of methodologies would be beneficial for the comparison and interpretation of results. In particular, we discuss anatomical location of the wounds, their size and depth, as well as the healing microenvironment (wet vs. moist vs. dry

Harnessing diversity and antagonism within the pig skin microbiota to identify novel mediators of colonization resistance to methicillin-resistant Staphylococcus aureus

“…Model systems to isolate and study the skin microbiota often rely on murine models. Fundamental differences in murine skin compared to human skin include morphological and histological differences such as thickness, the density of pilosebaceous units and other appendages such as sweat glands, and even distinct pathways and cell types involved in repair processes ( 20 - 22 ). Furthermore, many S. aureus virulence factors are attenuated in mice ( 23 ).…”

Integrating Single‐Cell and Spatial Transcriptomics Reveals Heterogeneity of Early Pig Skin Development and a Subpopulation with Hair Placode Formation

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An Advanced Review: Polyurethane-Related Dressings for Skin Wound Repair

“…In the field of skin healing, the pig model is considered to be a useful analog of human skin because it has many anatomical and physiological similarities and to human wound healing, and it is a better model for studying skin regeneration. Functional judgment of dressings in pigs would make the conclusions more clinically applicable [117].…”